feat: add service-based booking mode to appointment scheduling

- Introduced a new booking mode in WeeklySchedule to support service-based appointments.
- Updated SlotCalculatorService to calculate available start times based on selected service durations and buffer times.
- Enhanced AppointmentController to handle service items during booking, calculating slot_end on the server side.
- Implemented validation to ensure at least one bookable service exists for doctors in service mode.
- Added new API endpoint to retrieve available appointment slots based on selected services.
- Updated MyAppointmentsController to accept service items during appointment creation.
- Modified ServiceItem entity to include a bookable flag, allowing services to be marked for scheduling.
- Created migration to add bookable column to service_items table.
- Added tests for service-based slot calculations and validation logic.

src/Appointment/Entity/WeeklySchedule.php

@@ -15,10 +15,16 @@ class WeeklySchedule
     public const DAYS = ['saturday', 'sunday', 'monday', 'tuesday', 'wednesday', 'thursday', 'friday'];
 
     public const META_KEY = 'meta';
+
+    public const MODE_SLOT    = 'slot';    // نوبت‌دهی اسلاتی (رفتار پیش‌فرض)
+    public const MODE_SERVICE = 'service'; // نوبت‌دهی بر اساس مدت سرویس
+
     public const DEFAULT_META = [
         'online_booking_enabled' => true,
         'booking_window_value'   => 1,
         'booking_window_unit'    => 'month',
+        'booking_mode'           => self::MODE_SLOT,
+        'buffer_minutes'         => 0,
     ];
 
     #[ORM\Id]
@@ -82,6 +88,10 @@ class WeeklySchedule
             'booking_window_unit'    => in_array($meta['booking_window_unit'] ?? null, ['week', 'month'], true)
                 ? $meta['booking_window_unit']
                 : $current['booking_window_unit'],
+            'booking_mode'           => in_array($meta['booking_mode'] ?? null, [self::MODE_SLOT, self::MODE_SERVICE], true)
+                ? $meta['booking_mode']
+                : $current['booking_mode'],
+            'buffer_minutes'         => max(0, (int)($meta['buffer_minutes'] ?? $current['buffer_minutes'])),
         ];
         $this->updatedAt = time();
         return $this;